A Pentagon spokesperson said Saturday that Beijing and Washington have secured an understanding that China will return the captured underwater drone to the US. China's defense ministry also announced the same day local time that Beijing had decided to hand over the drone to the US side in an appropriate manner. Meanwhile, China also expressed its discontent over the US military's frequent close-up reconnaissance and military surveys within Chinese waters by vessels and aircraft.

In general, the military from both sides have exercised restraint. The two governments have shown their responsibilities in maintaining peace and stability in both the big picture of Sino-US cooperation and the South China Sea. Such an ending waved off concerns that the Chinese and US military might head for major crisis from a specific conflict.

Among US voices, the tweets by President-elect Donald Trumphave added the most fuel to the fire. His initial tweet said "China steals United States Navy research drone in international waters - rips it out of water and takes it to China in unpresidented act," in which he misspelled unprecedented, amusing American netizens. Later he posted another tweet saying "We should tell China that we don't want the drone they stole back. - let them keep it!" He seemed emotionally upset, but no one knows what he wanted to say.

Trump is not behaving as a president who will become master of the White House in a month. He bears no sense of how to lead a superpower. Even the US military did not use the term "steal" to describe the move by the Chinese navy. Trump's second tweet makes people worry that he will treat China-US relations as child's play.

Now people don't know if Trump is engaged in a psychological war with China or he is just unprofessional, even though he will be sworn in soon. Regarding the Sino-US relationship, he challenged the one-China policy and despised the principles which both countries have adopted to manage crises.

One thing for sure is that Trump has no leverages to maneuver the world, nor can he reshape China-US relations and the way the two major powers interact. Since he has not taken office, China has kept a calm attitude toward his provocative remarks. But if he treats China after assuming office in the same way as in his tweets, China will not exercise restraint.

It is possible that Trump is worried about his upcoming post and is eager to make waves against China so as to gain some leverage from China once he is sworn in. The Chinese government should be fully prepared for a hard-line Trump. We should show Trump what the one-China policy is and what bottom lines in Sino-US ties he should not touch. Once he does, he is bound to suffer the same losses that he makes China suffer from.